“Sherlock” season 4 may find fan favorites Benedict Cumberbatch and Martin Freeman flooded with difficulties in this much anticipated darkest season where the worst villain ever to set foot on 221 Baker Street will appear in the character of Culverton Smith (played by Toby Jones), Jim Moriarty and Charles Magnussen aside; the next helping of the show will also delve into Mary Watson’s (Amanda Abbington) past and give her and Freeman’s Doctor John Watson a chance to be newly fledged parents.

Get your Watson and your hansom out, Focus Interactive and Frogwares are taking you on a digital tour through Victorian London on the hunt for a master criminal. But don't worry, you'll have a master detective on your side!